We develop an approach for estimating net ecosystem exchange (NEE) using inventory-based information over North America (NA) for a recent 7-year period (ca. 2000–2006). The approach notably retains information on the spatial distribution of NEE, or the vertical exchange between land and atmosphere of all non-fossil fuel sources and sinks...
This study investigates the response of the global mean and spatial variations of the δ¹⁸O value of atmospheric CO₂ (δCₐ) to changes in soil CO₂ hydration rates, relative humidity, the δ¹⁸O value of precipitation and water vapor, visible radiation, temperature, and ecosystem flux partitioning. A three-dimensional global transport model was...
We examine the relation between δ¹⁸O in rainwater collected in southwestern Oregon
and climate variables including temperature, parcel trajectory, precipitation amount, and
specific humidity. Local surface air temperature at the time of sample collection explains a
large proportion of δ¹⁸O variability, suggesting that paleoclimatic archives that are related
to rainfall...
Although variations in insolation and emergent feedbacks among soil moisture,
vegetation, and soil cohesion are commonly invoked to explain topographic asymmetry that
depends on aspect, few studies have directly quantified the efficiency of regolith transport along
hillslopes of opposing aspect. We utilize meteoric ¹⁰Be concentrations in regolith (n = 74)...
Oxygen and strontium isotopic composition of sedimentary pore fluids obtained by drilling at the Chile Triple Junction have been used to obtain information on the diagenesis and transport mechanisms of fluids. Samples were collected from three sites located on an east-west transect of the pre-collision zone (Sites 859, 860, and...
We used a combination of seabird data (both fishery-dependent and fishery-independent) and fishing-effort data to evaluate the relative fisheries risk of five west coast groundfish fisheries and oneshrimp fishery to black-footed (Phoebastria nigripes), short-tailed (P. albatrus) and Laysan albatrosses(P. immutabilis). To assess risk, an overlap index was derived as the...
Background: Both sexes of bat flies in the families Nycteribiidae and Streblidae (Diptera: Hippoboscoidea) reside in the hair or on the wing membranes of bats and feed on blood. Members of the Nycteribiidae transmit bat malaria globally however extant streblids have never been implemented as vectors of bat malaria. The...
Intraseasonal variability of boreal summer rainfall and winds in tropical West Africa and the east Atlantic is examined using daily Tropical Rainfall Measuring Mission (TRMM) precipitation and the NCEP–NCAR reanalysis during 1998–2006. Intraseasonal precipitation variability is dominated by two significant spectral peaks at time scales near 15 and 50 days,...
It has generally been assumed by historians and anthropologists that the indigenous groups living to the west and northwest of the Colorado River were non-horticultural with three or four exceptions: some horticulture among the eastern-most Kamia, among the Chemehuevi who settled at a late date along the Colorado River, and...
The nearly completed U.S. West Coast (USWC) high-frequency radar (HFR) network provides an unprecedented capability to monitor and understand coastal ocean dynamics and phenomenology through hourly surface current measurements at up to 1 km resolution. The dynamics of the surface currents off the USWC are governed by tides, winds, Coriolis...